Silicon carbide (SiC) is a wide band gap semiconductor having a band gap larger than that of silicon (Si), which has been conventionally widely used as a material for semiconductor devices, and has a large breakdown field strength. Further, silicon carbide has an electron saturation speed and a heat conductivity higher than those of silicon, and thus silicon carbide has excellent characteristics as a semiconductor material for power semiconductor devices.
Regarding a silicon carbide substrate used as a material in a method for manufacturing a silicon carbide semiconductor device, for example, single crystal silicon carbide obtained by a sublimation method is cut into wafers, then an epitaxial layer is formed on the single crystal silicon carbide in which a side surface portion has been chamfered, and further, a process such as ion implantation is performed on the epitaxial layer. The ion implantation on the epitaxial layer is performed, for example, by forming a mask made of silicon dioxide (SiO2) on the epitaxial layer, and implanting ions through the mask.
Japanese Patent Laying-Open No. 2010-64918 (PTD 1) describes forming a silicon carbide epitaxial layer on a silicon carbide single crystal wafer in which a side surface portion of a silicon carbide substrate has been chamfered.